Food Storage is a problem in both home and commercial food preparation. Typically food is prepared well in advance of the time it is to be consumed and stored for a time prior to its use. Further, after a meal there will often be unconsumed food which is stored for future use.
The food storage containers customarily used to store food includes among other things dishes without covers. Dishes may be of many types and may have a substantially circular, rectangular, oval or eliptical and the like shaped openings. Although some of these dishes may be manufactured with fitted tops, many dishes do not have tops to prevent the contents from exposure to air, odors and to prevent the entry of particulate matter into the dish. In order to protect the dish's contents from air/odors and particulate matter it has been customary to use rectangular thermoplastic films to cover the dish's opening. The use of such films with respect to dishes has met with limited success due to the diversity in dish shapes and the diversity of materials from which dishes may be constructed. A common problem has been maintaining adherence of the film to the dish so as to maintain a reasonably controlled closure and maintain the film in contact with the dish.
Such a controlled closure is important in maintaining the freshness of food contained in the dish or in preventing accidental spillage of the contents by jarring or, e.g., by heating in a microwave oven, i.e. splattering. The ability of the film to adhere to the dish has been addressed in a number of commercially available film products. Cling additives have been introduced into such film compositions to improve their ability to adhere to dish surfaces and provide a controlled closure. Unfortunately, these cling additives are not effective on a wide range of surfaces and may exhibit different levels of adherence to the dish as a function of the temperature at which the dish is stored and the material employed for constructing the dish. In addition, these cling additives are not useful for some dishes formed of wood or certain plastics, since such cling additives are not generally effective in adhering to non-wetting surfaces.
Since the mechanism employed in providing adherence between thermoplastic films and a dish surface is not effective with all dish surfaces a need has developed to provide a more controlled closure means that is not dependent on the material from which the dish is constructed nor the temperature of the dish and its contents. Applicants have developed such a dish cover.
The general use of a dish cover itself is known in the prior art. U.S. Pat. No. 2,768,107 is representative of the heretofore known bowl/dish covers of the prior art. This patent describes a dish cover formed from a flat disc of thermoplastic material to which a tubular edging is secured by heat with pressure or by use of a cement or other adhesive. The tubular edging may contain an elastic cord, draw string or rigid ring. The tubular edging is attached to the flat disc by affixation at a time when both are linearly coextensive to provide for improved sealing of the flat disc and tubular edging. This cover is useful in the storage of food in dishes but is both difficult and expensive to make and, further, difficult to package. The formation of the flat disc sheet necessarily results in separate bowl covers that cannot be easily packaged in a convenient dispensing format.
Although the formation of dish covers formed from flat discs of thermoplastic material with sewn in elastic or an attached tubular edge section containing an elastic cord have utility, such have not heretofore found commercial success. The most widely used form of closure for dishes continues to be either a thermoplastic sheet film material or the enclosure of the entire dish in a plastic bag or other sealable container.
The instant invention solves the problem of commercial feasibility and technical acceptability by forming a dish cover of a rectangular flexible sheet material, preferably a thermoplastic film material, having an elasticized opening being generally characterized as a gusseted dish cover. The resulting gusseted dish covers may be formed in a continuous operation that avoids the need for forming several components for later assembly. Further, the gusseted dish cover may be combined on a center support to form integrated dish covers and dispenser.